I remember getting my first calculus exam back and feeling very proof-aggressed!
I was a "returning student" to SUNY @ Stony Brook to their Computer Science program (which also requires a number of engineering classes.) I had taken Calc I and II at a community college several years before, so they refused to accept my calculus credits, but the only class they had open that I could fit into my schedule was "Honors" calculus I, which was being taught by a visiting (full) professor from Hungary.
The very first class, she wanted to see what sort of experience the students had in math, so she asked us to pull out pens and paper, and to prove that between every two rational numbers, there's an irrational number, and that between every two irrational numbers, there's a rational number. My response (which was the same for about half of the class) was, "HUH?!?!?!?!?!"
I had no problem with her accent, since I have relatives from Eastern Europe, unlike some of the Chinese instructors and professors, I had, one, for digital logic, would occasionally lapse into Chinese during his lectures, and the Chinese students in the class would ask him questions in Chinese, and he'd answer in the same language. Every non-Chinese student (including 2 Indians) had to request a different instructor, and when denied, we were forced to drop the class.
Still, I did get a B+ in the Honors Calc class, but was able to get into a standard "Engineering Calculus II" class the next semester!
Mark